The large-aperture mirror deployment system is primarily designed to address the launch challenges posed by telescopes whose apertures exceed the constraints of the fairing envelope. It is imperative to ascertain that the stowed telescope adheres to the constraints imposed by the fairing envelope. The system must ensure that the stowed telescope conforms to the fairing envelope while minimizing the overall mass of the deployment mechanism and reducing actuator design complexity. To cope with the large number of design parameters and evaluation metrics, an optimization approach combining a multi-objective optimization algorithm with parameter correlation analysis is proposed to improve system performance. First, a multi-objective particle swarm optimization (MOPSO) algorithm incorporating penalty functions is introduced. By exploiting the coupling relationships among evaluation metrics, the number of optimization objectives is reduced. The penalty functions are then used as criteria to evaluate whether parameter schemes satisfy functional requirements of the deployment system, thereby enabling multi-objective optimization while ensuring the reliability of the algorithm outcomes. Subsequently, simulations are conducted by varying initial conditions (including parameter search bounds and the radial envelope of the stowed primary mirror) to analyze the correlations among initial conditions design parameters, and evaluation metrics. Finally, an optimal parameter scheme is selected by grouping evaluation metrics and applying a stepwise scoring and screening strategy. Compared with the original design, the optimal scheme achieves a 20.90% reduction in total mass, a 28.75% reduction in maximum equivalent moment of inertia, and reductions of 64.04% and 67.04% in the stroke lengths of the two rockers, respectively. The large-aperture mirror deployment system is then reconstructed based on the optimal parameters, and a random vibration analysis is performed under the stowed condition. The results demonstrate that, without changing the material, the optimized system continues to meet the required mechanical conditions.